Where Does Crime Data Come From?

Crime data comes from two general sources:

Observations
Reports
1a – Direct Crime Observations

Crime statistics can be gathered by observing criminal activity directly. Researchers can monitor criminal activities at locations which already have a history of criminal activity or they can monitor the persons frequently involved in criminal acts.

There are, although, some drawbacks to this method, such as the inaccuracies in calculated crime rates since just one location is observed, or the inability to measure the motivation behind the crimes.

1b – Experimental Crime Observations

Crimes can also be observed in terms of the response of bystanders and whitnesses. A branch of crime obervation called experimental observation involves staging a crime and then observing the actions of whitnesses. Other crime experiments involve measuring the impact of different criminal justice programs on similar criminal incidents.

The drawback to this method is that it doesn’t gather data on criminal motivations and actions. Neither does it study the relationship between the criminal and the victim.

2 – Crime Reports

Crimes are reported by:

Criminal Justice Agencies such as Police, Courts and Prisons
Victims
Offenders
2a – Reports from Criminal Justice Agencies

Crime reports generated by criminal justice agencies contain different information, with each type of report suited to the needs of the reporting agency. Additionally, data flows through these agencies and is subject to reductions at each step. As decribed by Sacco and Kennedy in The Criminal Event “Not all criminal events that come to the attention of the police result in an arrest, not all arrests result in a trial, and not all trials result in a conviction”. As a result, police reports are greater in number and detail and consequently are ideal for the measurement of crime.

Police reports cannot, although, be considered as an accurate count of the number of crimes since they are limited by the following:

not all crimes are reported by victims
not all police calls are determined to be crimes that should be reported
not all police departments underscore the importance of crime reports
The FBI collects crime data from police departments and has a system in place to standardize the data it receives. This system is called the Uniform Crime Reporting system (UCR). In this system, reports are categorized as follows:

murder-homicide
assault
robbery
rape
burglary
larceny-theft
motor vehicle theft
arson
Reports are collected from police departments accross the nation at the national, state, city, county and campus levels. These police departments VOLUNTARILY take the time to translate their crime data into the standardized UCR format and submit it to the FBI. The FBI then compiles this data into a annual report titled Crime in the United States. In addition to statistics on the eight offenses listed above, this annual includes statistics on:

crime volume
crime rate
violent crime
property crime
crime clearances
arrest rates
law enforcement employee totals
Not all data collection and distribution is voluntary. There is currently a Federal Law in affect titled the Campus Security Act which requires colleges and universities to collect specific “information with repect to campus crime statistics and campus security policies” and to “prepare, publish and distribute” this information” to all current students and employees, and to any applicant for enrollment or employment” upon request. The campus crime statistics must include a tally of the following reports:

murder
sex offenses, forcible or nonforcible
robbery
aggravated assault
burglary
motor vehicle theft
and a tally of the following arrests:

liquor law violations
drug abuse violations
weapons possessions
The FBI has made great steps toward standardizing crime reports, but their system contains some limitations. These limitations include the following:

since police departments voluntarily submit their data, the results do not include the information which was excluded.
when multiple crimes are committed by a single person or during a single event, only the more serious crime is reported
when one crime is committed by multiple people, depending on the crime, it may be reported as a single offense as in robbery or multiple offenses as in assault.
Because of these and other limitations, the FBI designed a new system called the National Incident-Based Reporting System (NIBRS). In this new system, the FBI will perform more of a collection and organizing task as their new system will break down and categorize crimes in a manner which more closely resembles the system used by police departments.

Unfortunately, there has been limited participation in the program due to various flaws in its design. The United States Department of Justice has hired an outside contractor to conduct a study of the NIBRS and to make recommendations.

2b – Reports from Victims

A crime report can also be generated by interviewing the victim of the offense. This can be a valuable source of information as many details about crimes are not reported to the police. These interviews are called victimization surveys. In these surveys the victim might be interviewed about their experiences before, during and after the offense occured.

The victimization survey performed by the United States Department of Justice is called the National Crime Victimization Survey (NCVS). In this survey, residents of the United States are contacted at random, usually by phone, and asked a series of questions. These questions are designed to determine who has been a victim of assault, burglary, larceny (personal and houshold), motor vehicle theft, rape and/or robbery. The victims responce to the crime is then sampled including whether they reported it to the police. In the event that the victim did not notify the police, the interviewer attemps to determine the reason.

This survey has posted an impressive response rate of 95%, but since victims usually experience strong emotions regarding their experience, not all their responces can be considered accurate. For example, domestic violence victims are usually reluctant to seek justice which may also include just reporting the crime . Additionally, this survey is prone to some of the same weaknesses of the UCR system. Only the most serious crime is reported and multiple victim crimes may not be recorded in enough detail.

It is important to understand the differences and similarities between these two crime reporting systems in order to make informed decisions concerning where crime data should be retreived. The United States Department of Justice has prepared a report which compares and contrasts these two systems. Additionally, the tutorial on the accuracy of crime data includes a table comparing the possible omissions in crime report data.